The study has been designed to show that effective and efficient screening for both ear disease and hearing loss can be carried out on children at a preschool age. Pure tone screening by itself may fail to identify children with otopathology while otolaryngological examination alone may miss hearing sensitivity losses which can lead to communication and education problems. The objective of the study is to show that by using both tympanometry and pure tone screening rarely will either ear disease or hearing loss be missed. Validation studies will be conducted at the Eye and Ear Hospital of Pittsburgh by giving each of 1500 children an otolaryngological and an audiological examination.